Copper
Die Cast Rotors

Why Choose Die-Cast Copper Rotor Motors?

• The Evolution of Induction Motors

AC Squirrel Cage Induction Motors originally featured ‘Copper Bar’ rotors with ‘End Rings’ brazed to the bars, creating a cage-like structure—hence the name Squirrel Cage Induction Motors. This design was the standard for nearly 60 years from 1900. As technology advanced, die-cast aluminum rotors were developed, streamlining production by eliminating the need for bar insertion and end rings. This innovation was quickly adopted worldwide and now dominates the low-tension Squirrel Cage Induction Motor market.

• The Rise of Die-Cast Copper Rotors

Copper, being the best conductor of electricity, prompted the question towards the end of the last century: “Why not Copper Die-Cast Rotors?” The main challenges were high melting temperatures, high heat conductivity, low die life, and other technical issues. Today, these hurdles have been overcome by a few manufacturers, including Kitra Industries (India), who now offer proven and high-performing Die-Cast Copper Rotors (DCR).

• Advantages of Die-Cast Copper Rotors

DCRs offer designers flexibility and the ability to achieve a wide range of performance and efficiency specifications. International experiences indicate that DCRs also provide material conservation and cost reduction opportunities in Induction Motors.
Despite initial challenges, Kitra Industries has successfully developed its own technology for manufacturing Copper Die-Cast Rotors. Today, we supply these rotors to motor manufacturers worldwide, with many recognizing and adopting the benefits of this new generation of rotors. We also offer sample rotors in desired sizes/designs for interested companies at a nominal die cost.
Our work has been highly appreciated by the Copper Development Association (USA) and the International Copper Promotion Council India (ICPCI).

• Benefits for Motor and Pump Manufacturers

• Reduced Losses – Greater Efficiency: Copper’s superior conductivity over aluminum reduces motor losses by 20-30% and rotor I²R losses by 40-50%, improving overall motor efficiency by at least 2-5%.
• Reduced Temperature Rise: Copper Die-Cast Rotors operate 10-12°C cooler than aluminum rotors, doubling the insulation life and increasing motor service life.
• Lower Manufacturing Cost: Proper selection of diameter and component sizes can reduce the overall motor cost by 7%.
• Better Momentary Overload Capacity: Copper Die-Cast Rotors withstand higher momentary overloads due to copper’s lower resistance.
• Higher Torque: Copper’s lower resistivity helps motors develop approximately 80% higher torque compared to aluminum rotors at the same slip.
• Sleek Design: Smaller component sizes result in a more compact motor design.
• Improved Pump Efficiency: Reduced losses enhance overall pump efficiency.
• Smoother Operation: Copper Die-Cast Rotors provide better dynamic balancing, ensuring smooth submersible pump operation.
• Increased Output: Higher speeds improve hydraulic efficiency by 60%, boosting pump output.
• Longer Pump Life: Lower operating temperatures extend insulation life, leading to a longer-lasting pump.

• Sample Rotors for Testing

Kitra Industries offers sample rotors at a nominal cost, enabling more motor manufacturers to test and realize the advantages of DCR. This facilitates the development of a new product line of high-efficiency motors with DCR.
Explore the attached pictorial presentation to understand the electrical, mechanical, and thermal advantages of Die-Cast Copper Rotors and the benefits they bring with this latest technology.